Neutrophils, an inflammatory cell type, are increasingly recognized as present in the airways of asthmatics, especially those with more severe disease. This research project was focused on the mechanisms by which neutrophils migrated into the airways of asthmatics. Although the initial studies suggested that LTB4 (a lipid mediator which can attract neutrophils into an inflammatory site) was elevated in the lungs of severe asthmatics, these initial observations have not proven out. Because of this, we have redirected our focus to the evaluation of the airway remodeling process seen in patients with severe asthma, primarily focused on the interactions between the growth factor, transforming growth factor beta and enzymes known as matrix metalloproteinases.